Search Results

Search found 6988 results on 280 pages for 'if statement'.

Page 193/280 | < Previous Page | 189 190 191 192 193 194 195 196 197 198 199 200  | Next Page >

  • Does this simple cache class need thread synchronization?

    - by DayOne
    Does this simple cache class need thread synchronization ... if I remove the lock _syncLock statement will encounter any problems? I think i can remove the locks as the references should be updated correctly right? ... BUt i'm think whar happens if client code is iterating over the GetMyDataStructure method and it get replaced? Thanks! public sealed class Cache { private readonly object _syncLock = new object(); private IDictionary<int, MyDataStructure> _cache; public Cache() { Refresh(); } public void Refresh() { lock (_syncLock) { _cache = DAL.GetMyDataStructure(); } } public IDictionary<int, MyDataStructure> **GetMyDataStructure**() { lock (_syncLock) { return _cache; } } }

    Read the article

  • Do "if" statements affect in the time complexity analysis?

    - by FranXh
    According to my analysis, the running time of this algorithm should be N2, because each of the loops goes once through all the elements. I am not sure whether the presence of the if statement changes the time complexity? for(int i=0; i<N; i++){ for(int j=1; j<N; j++){ System.out.println("Yayyyy"); if(i<=j){ System.out.println("Yayyy not"); } } }

    Read the article

  • MySQL Join Comma Separated Field

    - by neeraj
    I have two tables. First Table is a batch table that contain comma separated student id in field "batch" batch -------------- id batch -------------- 1 1,2 2 3,4 Second Table is marks marks ---------------------- id studentid subject marks 1 1 English 50 2 2 English 40 3 3 English 70 4 1 Math 65 5 4 English 66 6 5 English 75 7 2 Math 55 How we can find those students of first batch id =1 who have scored more than 45 marks in English without using sub query. Problem i found to get this done using a single query is that we can not use IN as an association operator in JOIN statement What changes are required in below query to make it work? SELECT * FROM batch INNER JOIN marks ON marks.studentid IN(batch.batch) where batch.id = 1

    Read the article

  • c++ lists question

    - by mousey
    I want put a value from front of the list into an another list but I am getting an error. for exmaple List<int> li; List<int> li2; ............. ............. li2.push_back(li.front()); // this statement doesnt work for me. Can someone please help me. example code: list li; list li2; li.push_back(1); li.push_back(2); li.push_back(3); for(int i=0;i<3;i++) { cout<<li.front()<<endl; li2.push_back(li.pop_front()); }

    Read the article

  • using Cookie-free Domains for Components

    - by JPro
    I was looking at the post here which says When the browser makes a request for a static image and sends cookies together with the request, the server doesn't have any use for those cookies. So they only create network traffic for no good reason. Although I tend not to use cookies at all, my doubt is I used to think that the server creates the cookies to store the session varialbles etc and sends to the client. But this statement says the reverse of that. I don't quiet understand what is the need for the browser to create and send cookies with the request, to me it doesn't make any sense?. Can anyone please correct me? Thanks/.

    Read the article

  • Dowloading a bunch of files asynchronous wait till last finished

    - by Casper Broeren
    I'm trying to download a lot of files after downloading a sql statement must insert a record. I'm using System.Net.Client to download each file synchronously, still it could be done asynchronous. There's no relation or dependency between each download. At first I just tried to use WebClient.DownloadFileAsync but that shutted the program down and killed all the download processes/threads. Second I tried to create a wait routine something like this; while (processedFiles < totalFiles) Thread.Sleep(1000) This freezed everything. So could someone tell me which aproach to take to implement this Async?

    Read the article

  • Exit Try/Catch to prevent code after from being run

    - by coffeeaddict
    I've got for example a try/catch in my method: } catch (OurCustomExceptionObject1 ex) { txtErrorMessage.InnerHtml = "test 1"; } catch(OurCustomExceptionObject2 ex) { txtErrorMessage.InnerHtml = "test 2"; } catch (OurCustomExceptionObject3 ex) { txtErrorMessage.InnerHtml = "test 3"; } ... rest of code here is being executed after the try/catch I do not want the rest of code to run if any of the exceptions are caught. I'm handling the exceptions. I heard do not use Exit Try for some reason. Is that true, it's bad to do this? Is this the right way to halt execution of code thereafter the catch statement?

    Read the article

  • How do you escape double quotes inside a SQL fulltext 'contains' function?

    - by Richard Davies
    How do you escape a double quote character inside a MS SQL 'contains' function? SELECT decision FROM table WHERE CONTAINS(decision, '34" AND wide') Normally contains() expects double quotes to surround an exact phrase to match, but I want to search for an actual double quote character. I've tried escaping it with \, `, and even another double quote, but none of that has worked. P.S. I realize a simple example like this could also be done using the LIKE statement, but I need to use the fulltext search function. The query I provided here has been simplified from my actual query for example purposes.

    Read the article

  • DB2 increase bufferpool size and compressed tables not equal better performance. Why?

    - by Mestika
    Hi, I’m working on tuning and increasing the performance of my IBM DB2 version 9.7 database. I’ve been searching around the net for the last couple of days and learned that if I created my tables in COMPRESS mode and created one more bufferpool and set both of them to access 1024mb, then the performance in my queries should increase because of the less I/Os to the disks. However, when I run my time analysis, the performance Decrease. I added the new additions to my regular database with the indexes I’ve used all the time. Each time I search google I come up with the statement that: Increased bufferpool size and several bufferpools AND a table compression SHOULD prove to get better performance. I’m very puzzled about the total unexpected result. Are there some tuning mechanisms I’ve forgot or does anyone have a explanation for this odd behavior? Sincerely Mestika

    Read the article

  • C++ and preprocessor macro gotcha

    - by aaa
    hello. Appologies for yet another gotcha question. Can you figure out what is wrong with the statement below? gcc error states: "type name declared as function returning array". #define MACRO(a) (a)[1] class index { typedef int index_type[2]; index_type& operator[](int i); }; int k = 0; int i = MACRO(index()[k]); ps: is such questions are deemed too annoying, I am going to stop.

    Read the article

  • Is there a way to inspect all controller variables at once in Rails?

    - by m.u.sheikh
    I am exploring an big controller method, with about 10 or so instance variables. Some of them are set in before_filter methods, and some others inside the method itself. I want to inspect them with puts, but dont want to write all of them out example: puts "var1: #{@var1.inspect}....var15: #{@var15.inspect}" Is there a generic method that will display all the instance variables with an @ sign set so far in the current method? If not, what is the next best way to inspect all of them at once without having to write all of them in a puts statement?

    Read the article

  • Is it possible with dynamic TSQL query ?

    - by eugeneK
    I have very long select query which i need to filter based on some params, i'm trying to avoid having different stored procedures or if statements inside of single stored procedure by using partly dynamic TSQL... I will avoid long select just for example sake select a from b where c=@c or d=@d @c and @d are filter params, only one can filter at the same time but also both filters could be disabled. 0 for each of these means param is disables so i can create nvarchar with where statement in it... How do i integrate in here dynamic query so 'where' can be added to normal query. I cannot add all the query as big nvarchar because there is too many things in it which will require changes ( ie. when's, subqueries, joins)

    Read the article

  • Hiding result sets from multiple selects in a stored procedure

    - by Josh Young
    I have a stored procedure that retrieves SQL queries as text and executes the statements using sp_executesql. Each of the dynamic queries is a count query in that it only returns the number of records found (select COUNT(id) from...). I am looping through a set of SQL queries stored as text and building a table variable out of the results. At the end, I am selecting all the results from the table variable as the result set that I want returned from the stored procedure. However, when I execute the stored procedure, I am naturally getting multiple result sets (one for each of the dynamic queries and one for the final select.) Is there any way I can suppress the results of a select statement executed through sp_executesql? I have found answers that reference storing the results in a temp table, but I don't have control of the query text that I am running so I can't change it to select into anything. Please help. Thank you for your time.

    Read the article

  • How to UNION ALL two SELECT statements?

    - by Lisa
    I have 2 tables, one looks like this: TABLE ONE id | Last Name | First Name | Username | Password | Secret Question and another that looks like this: TABLE TWO id | Hobby | Country | I want to combine a Select statement that grabs data from both tables and output the results. The following code: $select = mysql_query(" SELECT * FROM table_one WHERE Username = 'Bob' UNION ALL SELECT * FROM table_two WHERE Hobby = 'Baseball' "); while ($return = mysql_fetch_assoc($select)) { $userName = $return['Username']; $hobby = $return['Hobby']; } echo "$userName likes $hobby"; results in a The used SELECT statements have a different number of columns error, what am I doing wrong?

    Read the article

  • In SQL find the combination of rows whose sum add up to a specific amount (or amt in other table)

    - by SamH
    Table_1 D_ID Integer Deposit_amt integer Table_2 Total_ID Total_amt integer Is it possible to write a select statement to find all the rows in Table_1 whose Deposit_amt sum to the Total_amt in Table_2. There are multiple rows in both tables. Say the first row in Table_2 has a Total_amt=100. I would want to know that in Table_1 the rows with D_ID 2, 6, 12 summed = 100, the rows D_ID 2, 3, 42 summed = 100, etc. Help appreciated. Let me know if I need to clarify. I am asking this question as someone as part of their job has a list of transactions and a list of totals, she needs to find the possible list of transactions that could have created the total. I agree this sounds dangerous as finding a combination of transactions that sums to a total does not guarantee that they created the total. I wasn't aware it is an np-complete problem.

    Read the article

  • Newbie SQL joining question: houses, refrigerators, and apples

    - by Philip Brocoum
    There are three tables in my database: apples, refrigerators, and houses. Each apple belongs to a refrigerator (it has a column that references the refrigerator that it's in), and each refrigerator belongs to a house. The problem is, each apple ALSO belongs to a house. I guess this isn't "normalized" or whatever, but it's the way it is. Obviously, each apple should belong to the house that its refrigerator belongs to. An apple can't be in two different places at once, after all. So, my question is this: what SQL statement will allow me to find all of the "bad apples" that for some reason incorrectly reference a different house than the refrigerator that they are supposedly in. In other words, I need to find the apples that contain contradictory information. I don't know if this is a "join" question or not, but I'm sure there's probably a very straightforward way of figuring this out. I just don't know what it is. Thanks for your help!

    Read the article

  • While Loop in TSQL with Sum totals

    - by RPS
    I have the following TSQL Statement, I am trying to figure out how I can keep getting the results (100 rows at a time), store them in a variable (as I will have to add the totals after each select) and continue to select in a while loop until no more records are found and then return the variable totals to the calling function. SELECT [OrderUser].OrderUserId, ISNULL(SUM(total.FileSize), 0), ISNULL(SUM(total.CompressedFileSize), 0) FROM ( SELECT DISTINCT TOP(100) ProductSize.OrderUserId, ProductSize.FileInfoId, CAST(ProductSize.FileSize AS BIGINT) AS FileSize, CAST(ProductSize.CompressedFileSize AS BIGINT) AS CompressedFileSize FROM ProductSize WITH (NOLOCK) INNER JOIN [Version] ON ProductSize.VersionId = [Version].VersionId ) AS total RIGHT OUTER JOIN [OrderUser] WITH (NOLOCK) ON total.OrderUserId = [OrderUser].OrderUserId WHERE NOT ([OrderUser].isCustomer = 1 AND [OrderUser].isEndOrderUser = 0 OR [OrderUser].isLocation = 1) AND [OrderUser].OrderUserId = 1 GROUP BY [OrderUser].OrderUserId

    Read the article

  • two line label with expression

    - by metasequoia
    I'd like to write an axis label over two lines with an expression() statement. However, plotmath and expression won't allow this (e.g. subscript appear on the far right). I found this discussion circa 2005 of a similar issue but the work around that they offer doesn't translate to my application in ggplot2. A recent question addressed a a different permutation of multi-line expression statements, but again the work around provided doesn't apply here. Example: p <- ggplot(mtcars,aes(x=wt,y=mpg))+ geom_point()+ xlab(expression(paste("A long string of text goes here just for the purpose \n of illustrating my point Weight "[reported]))) try(ggsave(plot=p,filename=<some file>,height=4,width=6)) yields an image where subscript "reported" is kicked out to the right when I'd like it to sit next to the previous word.

    Read the article

  • Multiple user database design

    - by dieguitoweb
    I have to develop a basic social network for an academic purpose; but I need some tips for the users management.. The users are subdivided into 3 groups with different privilege: admins,analysts and standards users. For every user should be stored into the database the following information: name,lastname,e-mail,age,password. I'm not quite sure how I should design the database between theese two solutions: 1)one table called 'users' with the 'role' attribute that explain what a user can do and what can't do, and the permissions are managed via php 2)every application user is a database user created with the query 'CREATE ROLE' (It's a postgres database) and he has permissions on some tables granted with the 'GRANT' statement You should take into account that the project is for a database exam.. thanks

    Read the article

  • Use a named custom column in SQL 2005 in WHERE clause?

    - by Orange Kid
    Can I name a custom column in the SELECT statement and reference that in the WHERE clause without duplicating code? For example; SELECT RIGHT(REPLICATE('0', 5) + RTRIM(SOME_ID)), 5) AS DISPLAY_ID FROM dbo.MY_TABLE WHERE DISPLAY_ID LIKE '%005%' Only much more complicated. I want to maintain this code in one place only but SQL Server 2005 forces me to duplicate the custom SELECT in the WHERE clause. I believe this was possible in Microsoft SQL Server 2000 but no longer in 2005. Thanks.

    Read the article

  • Weird behavior in referring to global variable. Is this a bug in javascript? Surely it isn't!

    - by Chandan .
    Consider the following piece of code. <html> <body> <script> var x = 5; //globally declared function showX() { alert("x="+x); //trying to display global value var x=10; //trying to create and initialize a local x } </script> <input type = "button" value="Show X" onclick="showX()"> </body> </html> The alert statement shows 'x=undefined'. And doesn't print the global value of x as expected. An equivalent java code would display 5! So, is it a bug? If not then how does one explain that behavior?

    Read the article

  • Why did the C# designers attach three different meanings to the 'using' keyword?

    - by gWiz
    The using keyword has three disparate meanings: type/namespace aliasing namespace import syntactic sugar for ensuring Dispose is called The documentation calls the first two definitions directives (which I'm guessing means they are preprocessing in nature), while the last is a statement. Regardless of the fact that they are distinguished by their syntaxes, why would the language developers complicate the semantics of the keyword by attaching three different meanings to it? For example, (disclaimer: off the top of my head, there may certainly be better examples) why not add keywords like alias and import? Technical, theoretical, or historical reasons? Keyword quota? ;-) Contrived sample: import System.Timers; alias LiteTimer=System.Threading.Timer; alias WinForms=System.Windows.Forms; public class Sample { public void Action { var elapsed = false; using(var t = new LiteTimer.Timer(_ => elapsed = true) { while (!elapsed) CallSomeFinickyApi(); } } } "Using" is such a vague word.

    Read the article

  • Oracle: TABLE ACCESS FULL with Primary key?

    - by tim
    There is a table: CREATE TABLE temp ( IDR decimal(9) NOT NULL, IDS decimal(9) NOT NULL, DT date NOT NULL, VAL decimal(10) NOT NULL, AFFID decimal(9), CONSTRAINT PKtemp PRIMARY KEY (IDR,IDS,DT) ) ; SQL>explain plan for select * from temp; Explained. SQL> select plan_table_output from table(dbms_xplan.display('plan_table',null,'serial')); PLAN_TABLE_OUTPUT -------------------------------------------------------------------------------- --------------------------------------------------------------- | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| --------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | 61 | 2 (0)| | 1 | TABLE ACCESS FULL| TEMP | 1 | 61 | 2 (0)| --------------------------------------------------------------- Note ----- - 'PLAN_TABLE' is old version 11 rows selected. SQL server 2008 shows in the same situation Clustered index scan. What is the reason?

    Read the article

  • conditional while loop in php?

    - by julio
    I'm pretty sure there's an obvious answer for this-- hoping someone can help me-- I need to do a PHP while loop, but only if a variable is true. And I can't really put the while loop in an "if" statement, which seems like the obvious thing to do, since the code block is huge and it would be ugly and confusing. Do I need to break out the code in the loop into a function, or is there an easier way to deal with this? Here's the basic idea: if(condition){ while(another_condition){ //huge block of code loops many times } } else { // huge block of code runs once } I want the huge block of code to execute regardless of the state of the condition variable-- but only to execute once if condition is false, and execute for as long as another_condition is true if condition is true. Hope that's clear! The following code doesn't work, but gives an idea of what I want to accomplish: if(condition){ while(another_condition){ } // huge block of code if (condition){ } } // closes the while loop-- obviously throws an error though! thanks in advance.

    Read the article

  • Which class will be instantiated

    - by Michael
    Say I have 2 subclasses from UIViewController, class A and class B. In Main nib file an object is representing class A and it is set to load file from Secondary nib file. The owner of Secondary nib is of class B. The question is - from which class an object in Main nib file will be instanciated once the nib files unarchived in the memory? The reason this question arised is that I have to take care myself if such reference to external NIB file present, to ensure that the first nib's object and second nib's owner is same. Please correct me if my statement is wrong.

    Read the article

< Previous Page | 189 190 191 192 193 194 195 196 197 198 199 200  | Next Page >